Knife sharpener attachment



Aug. 23, 1960 A. c. DE ANGELIS ETAL 2,949,709 KNIFE SHARPENER ATTACHMENT Filed April 15, 1958 3 Sheets-Sheet l INVENTORJ ATT RIVEY 1960 A. c. DE ANGELIS ET AL 2,949,709

KNIFE SHARPENER ATTACHMENT Filed April 15, 1958 3 Sheets-Sheet 2 lid) INVENTOR/S flizyelo CI Deflngelis W ww m gzegi ztgux hTT NE Y 1960 A. c. DE ANGELIS ET AL 2,949,709

-KNIFE SHARPENER ATTACHMENT Filed April 15, 1958 3 Sheets-Sheet 3 INVENTORS KNIFE SHARPENER ATTACHMENT Filed Apr. 15, 1958, Ser. No. 728,609

1 Claim. (Cl. 51-128) The present invention relates to improvements in devices for sharpening knives and similar tools and is concerned particularly with knife sharpening devices in the form of attachments to be mounted upon the drive shaft of an electric motor such as that usually provided in the bases of electric motor driven blenders.

A principal object of the invention is to provide a knife sharpening device wherein an oscillating motion is imparted to the grinding stone whereby the stone moves in an orbital path thus to provide a honing action for the knife or other tool which is held in stationary position against the stone or drawn across the same by the operator. In consequence no skill is required on the part of the user and knives or other tools may be readily and uniformly sharpened in a rapid manner without danger of oversharpening or impairing the temper of the blade.

A more specific object of the invention is to provide a floating mounting means for the grinding stone including a resilient sleeve which is adapted to flex as the stone moves in its orbital path and which further provides a protective closure for the stone operating means.

Other and further objects and advantages will be apparent from the following detailed explanation taken in conjunction with the accompanying drawings wherein a preferred embodiment of the principles of the invention has been selected for exemplification.

In the drawings:

Fig. 1 is a top plan view of a knife sharpening attachment constructed in accordance with the present invention;

Fig. 2 is a side elevational view of the device;

Fig. 3 is a bottom view of the device;

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 1 and showing the device mounted in operative position upon the base of a blender which is indicated in fragment;

Fig. 5 is a sectional view Fig. 1;

Fig. 6 is a plan view with the top cover of the device removed;

Fig. 7 is a detailed section taken on the line 7-7 of Fig. 5; and F Fig. 8 is a detailed section taken on the line 8-8 of Referring more particularly to the drawings, wherein like numerals refer to like parts, the device, indicated in its entirety at 10, has a base or lower skirt portion 12 which is provided with mounting means such as a series of circumferential recesses 14 adapted for mating engagement with the upright container supporting fingers F of an electric blender base fragmentarily indicated at B in Fig. 4. US. Patent No. 2,761,659 is illustrative of such an electric motor driven blender base. Of course, other forms of mounting means may be provided to adapt the base 12 for attachment to other forms of blenders or electric motor drives.

The base 12 includes a transverse web portion 16 having a central cylindrical housing 18 and spaced surroundtaken on the line 55 of ate ing apertures 20. The transverse web portion 16 may also be provided with an upright annular shoulder 22 and an upright peripheral rim 23 for purposes to be hereinafter explained. Reinforcing ribs such as indicated at 21 may be provided as desired. The base portion 12 including its various parts as shown and described may be and preferably is cast as an integral unit.

A cylindrical bearing 24 which may be powdered bronze is mounted axially within the housing 18 in any suitable manner such as by a retainer ring 26 and wicks 30 of oil retaining felt may be provided for lubricating the bearing. A drive shaft 32 is mounted for rotation in the bearing member 24 and is provided at its bottom end with a filleted recess 34 for receiving in driving engagement the upright extended end of the motor drive shaft as indicated at S in Fig. 4. The upper end portion of the drive shaft 32 carries an upwardly projecting drive pin 36 eccentric to the axis of rotation of the shaft 32. A counterweight 37 is preferably secured to the shaft 32 opposed to the eccentric drive pin 36 to reduce vibration and to induce smoother operation.

As a feature of the invention the mounting means for the grinding or honing stone 38 includes an upright collar or sleeve 40 of resilient rubber or suitable plastic material, neoprene for example, which is adapted to flex as the stone describes its orbital path. The collar or sleeve 40 may be mounted on the base 12 by an annular disc 42 engaging the lower peripheral edge of the collar and which in turn is secured to the upright annular rib portion 22 of the base 12 by screws 44. A motion-transmitting and stone supporting member 46 is secured, such as shown, to the upper end portion of the collar 40 and is provided with an annular depending sleeve for receiving a cylindrical bearing 48, preferably of doubled shielded ball bearing type. As shown, the eccentric drive pin 36 projects through the bearing 48 and its extended threaded end is engaged by a nut 49 to secure the assembly together. Spaced tabs 50 project upwardly of the bearing holder 46 and upwardly of the resilient supporting collar 40 for engaging peripheral edge portions of the stone 38 which thus may be secured to the upper surface of the bearing holder 46, through the medium of suitable shims 52 if desired. As shown, the walls of collar 40 preferably slightly taper inwardly and upwardly.

It will be apparent that when the attachment is operatively positioned upon a blender and the drive shaft 32 is rotated by the blender electric motor at high speed, which may be of the order of 14,000 r.p.m., the eccentric drive pin 36 in engagement with the bearing 48 imparts an oscillatory motion to the holder 46, the stone 38 and also to the resilient collar 40. Thus, the stone 38 at the upper free end portion of the resilient collar 40 is moved rapidly in an orbital path which is the complement to a. conventional honing motion usually applied to blades for honing purposes. The resilient collar 40 flexes as the stone 38 oscillates as indicated by its straight wall shown at the left hand side of Fig. 4 and provides a damping efiect on the motion of the stone. The flexible collar 40 also tends to damp the operating noise of the device and provides a dust-proof housing for the operating mechanism of the stone.

A suitable cover 54 for the device is supported by the upright peripheral rim 23. The cover is centrally apertured to provide access to the stone 38 and preferably has opposed upper wall portions 56 slanting inwardly toward its center portion for supporting a knife blade at an appropriate angle for sharpening during either right hand or left hand use of the device. A spring member 58 may be secured to the upper surface of the cover 54 in any suitable manner such as by the screw means 59 shown and includes wing members 60 which bear against the inclined walls 56 of the cover to retain the knife blade in desired angular position.

It is to be understood that the present invention is not confined to the precise construction and arrangement of parts as herein illustrated and described but embraces all such modifications thereof as may come within the scope of the following claim.

We claim:

A knife sharpener attachment adapted to be driven by an electric motor driven shaft which comprises a base having an upright annular shoulder and an upright peripheral rim, a first cylindrical bearing mounted axially Within said housing, a drive shaft mounted Within said bearing adapted at its lower end for engagement with said motor driven shaft, an upwardly projecting drive pin eccentrically mounted on the upper end of said drive shaft, a counterweight secured to said shaft opposite said drive pin, an upright resilient sleeve secured at its lower end to said annular shoulder, a second cylindrical bearing mounted on said drive pin, a circular support and motion transmission member having an annular depending sleeve receiving said cylindrical bearing and secured to the upper end of said resilient sleeve, tabs extending upwardly from said circular support member, a sharpening stone mounted on said support member between said tabs whereby rotation of said shaft imparts an orbital motion to said stone, a knife guide mounted on said upright pe- \ripheral rim above said stone for supporting a knife blade at an appropriate angle for sharpening.

References Cited in the file of this patent UNITED STATES PATENTS 2,077,195 Adams Apr. 13, 1937 2,267,938 McCrum Dec. 30, 1941 2,270,309 Kehle Jan. 20, 1942 2,367,668 Champayne Ian. 23, 1945 2,441,506 Osman May 11, 1948 2,722,783 ORussa Nov. 8, 1955 2,751,725 Champayne June 26, 1956 2,771,111 Seyfried Nov. 20, 1956 2,798,701 Collura July 9, 1957 2,841,931 Holzhausen et a1. July 8, 1958 

